How to Read Saju for Overseas Births Using Local True Solar Time
How should the Saju chart of someone born overseas be calculated?
Many people convert the birth time into Korean time and then enter it into a Manse-ryeok calendar. In Daedeok Myeongri, however, calculating Saju this way makes it difficult to reflect the actual position of the sun at the moment of birth.
For overseas births, the important standard is not Korean time. It is the local natural time of the city of birth, calculated from the local date and clock time after correcting for daylight saving time and longitude.
If the birth time changes by only 30 minutes to one hour, the hour pillar can change. If the birth occurred near midnight, even the day pillar can change. For that reason, an overseas birth chart should be calculated through the following four steps.
Why Overseas Birth Saju Should Not Be Converted Into Korean Time
Saju Myeongri analyzes a person's innate energy through the year, month, day, and hour pillars at the moment of birth.
Daedeok theory in particular interprets Saju through seasonal change and the movement of the sun. Therefore, no matter which country a person was born in, the chart should not be calculated by Korean time. The Saju pillars should be determined by where the sun was in the sky of the birth location.
For example, if someone was born in New York, simply converting that birth time into Korean time can change the date and time significantly. But the season and solar position at the moment of birth were formed under the local sky of New York.
Therefore, an overseas birth Saju chart must be calculated from the local time of the country and city of birth.
Step 1. Confirm The Local Birth Date And Standard Clock Time
The first step is to confirm the local birth date and clock time recorded on the birth certificate or other official record.
Countries around the world use standard time zones based on the 0-degree longitude of the Greenwich Observatory in the United Kingdom. Because Earth rotates 360 degrees in 24 hours, a time difference of about one hour occurs for every 15 degrees of longitude.
At this stage, the following information should be checked.
- Birth year, month, and day
- Local birth time recorded on the birth certificate
- Birth country and city
- The time zone used at the time
- The state, province, or administrative region of the birthplace
Even within the same country, time zones can differ by region. In large countries such as the United States, Canada, and Australia, the birth city and state or province must be confirmed.
Step 2. Check Whether Daylight Saving Time Applied
The most commonly missed factor in overseas birth Saju calculation is daylight saving time.
Daylight saving time is a system that usually moves the clock one hour forward during seasons with longer daylight. If daylight saving time was in effect at the moment of birth, the recorded clock time generally has to be moved back by one hour to return it to standard time.
For example, even if the birth certificate records 3:00 p.m., if daylight saving time was active, the standard time becomes 2:00 p.m.
However, the use of daylight saving time, as well as its start and end dates, differs by country and region. Even in the same region, the rules may have changed depending on the birth year. To read an overseas birth Saju chart accurately, the daylight saving record for the exact birth year and region must be checked.
Step 3. Correct Natural Time By The Longitude Of The Birth City
After removing daylight saving time, the next step is to calculate natural time based on the actual longitude of the birth city.
Not every city inside one standard time zone is located on the same longitude. If the standard meridian used by the country differs from the actual longitude of the birth city, a gap appears between clock time and the movement of the sun.
A difference of one degree in longitude is approximately four minutes in time.
Natural-time correction = difference between the actual longitude of the birthplace and the standard meridian x 4 minutes
If the birthplace is east of the standard meridian, natural time becomes earlier. If it is west of the standard meridian, natural time becomes later.
Let us use Korea as an example. Korean Standard Time is based on 135 degrees east longitude, but if we view the central part of Korea as being around 127.5 degrees east, there is a difference of about 7.5 degrees.
7.5 degrees x 4 minutes = about 30 minutes.
Therefore, when the clock shows noon, the natural time based on the sun's position can be calculated as approximately 11:30 a.m. Overseas birth Saju applies the same principle by using the longitude of the birth city.
Step 4. Confirm The Saju Chart With The Corrected Local Natural Time
Finally, enter the time that reflects all of the following corrections into the Manse-ryeok calculation.
- Confirm the local date and time recorded on the birth certificate.
- Check whether daylight saving time was applied at birth.
- If daylight saving time was applied, return the time to standard time.
- Correct the difference between the standard meridian and the actual longitude of the birth city.
- Calculate the Saju chart from the final local natural time.
The hour pillar is confirmed based on this final corrected birth time.
This is especially important when the birth time is close to the Zi hour or near the boundary between hour pillars. A correction of only several dozen minutes can change the hour pillar. For people born near midnight, the correction may move the birth date to the previous or next day, changing the day pillar as well.
Example Of Overseas Birth Saju Calculation
Suppose someone was born in a city in the United States at 1:20 a.m. local time.
- Birth certificate record: 1:20 a.m.
- Daylight saving time applied: subtract 1 hour
- Returned to standard time: 12:20 a.m.
- Longitude correction for the birth city: about 20 minutes earlier
- Final local natural time: close to 11:60 p.m. on the previous day
As this example shows, daylight saving and longitude correction can change the birth date. If the date changes, not only the hour pillar but also the day pillar and the entire Saju structure can change.
For that reason, an overseas birth chart should not be calculated from the country name alone. The birth city, birth year, local time zone, and daylight saving status must all be checked together.
Common Mistakes When Calculating Overseas Birth Saju
Converting The Birth Time Directly Into Korean Time
This is the most representative error. Overseas birth Saju should be calculated from the local birth date and the sun's position in the place of birth, not from Korean clock time.
Applying Current Time-Zone Rules To A Past Birth Year
Time zones and daylight saving systems have changed many times throughout history. The actual rules for the birth year should be checked, not only the current rules.
Using The Longitude Of The Capital City Instead Of The Birthplace
Even within the same country, each city has a different longitude. The calculation should use the actual longitude of the birth city, not the longitude of the capital city.
Correcting Daylight Saving Time Twice
Some Manse-ryeok programs automatically process time zones and daylight saving time. If you use a time that has already been corrected by the program and subtract one hour again, it becomes a double correction. This should be avoided.
Are Local Natural Time And True Solar Time The Same?
In practical Saju work, the time corrected by longitude is often called natural time or true solar time.
Strictly speaking, however, when the terms are separated astronomically, time corrected only by longitude is closer to local mean solar time. True solar time may additionally reflect the equation of time, which accounts for the date-specific movement of the sun.
Therefore, it is useful to check whether the Manse-ryeok program or Myeongri theory being used applies only longitude correction or also applies the equation of time. If different programs produce different Saju charts, this setting should be compared first.
The Key To Overseas Birth Saju Is The Sky Of The Birthplace
When reading an overseas birth Saju chart, the core issue is not simple time-zone conversion.
Confirm the local birth date and time -> correct daylight saving time -> correct the longitude of the birth city -> confirm the final Saju chart by local natural time.
Only after these four steps can the season and solar position of the birthplace at the moment of birth be properly reflected in the Saju chart.
If you were born overseas or want to check the Saju chart of a family member born abroad, prepare the following information.
- Exact birth year, month, and day
- Local time recorded on the birth certificate
- Birth country and city
- State, province, or administrative region of birth
- Whether daylight saving time was applied at birth
In Saju, a difference of only several dozen minutes can change the starting point of interpretation. If you were born overseas, do not simply convert your birth time into Korean time. First check whether the local natural time of the birthplace has been calculated accurately.
For overseas births, even if you entered your chart yourself, daylight saving correction and birth-city longitude correction are still required. After entering your chart, please request consultation through KakaoTalk. If you want SajuCM naming service for a child born overseas, create an account, enter your own chart, choose the naming request menu, and then enter the child's birth date and time.
English Saju And Naming Consultation
Child Saju-based naming service | SajuCM
Related Consultation Links
These English SajuCM pages are useful next steps for this topic.